Yarn break detector

ABSTRACT

A yarn break detector is disclosed particularly for twisting machines used for plying two or more yarns. The arrangement includes a switch operated by a drop wire means which is positioned between the feed mechanism and the twisting and takeup means and holds the two yarns separated from each other in such manner that breakage of either or both yarns change the condition of the switch. A switch which is particularly adaptable to this environment is also disclosed.

United States Patent Adams [451 June 27, 1972 1 1 YARN BREAK DETECTOR 2,754,653 7/1956 Adams ..s7/s1 [72] Inventor: Cecil S. Adams, Greenville, S.C. FOREIGN PATENTS OR APPUCA'HQNS 1 1 Assisnw Adams Incorporated, Grenville, 1,170,840 5/1964 Germany ..57/86 22 F! 2 7 1 l9 0 Primary Examiner-Wemer H. Schroeder [21] Appl. No.: 84,830 Attorney-Kemon, Palmer & Estabrook 5 7 ACT [52] 0.8. CI ..57/8l 1 [51] Int. Cl. ..D0lh 13/16 A y break detector is disclosed p i u rly f r i ing 58 Field of Search ..s7/19, 61,78, so, 81; 242/37, machines used for plying two or more yams- The arrangement 2 23 5 66/163; zoo 1 3 includes a switch operated by a drop wire means which is positioned between the feed mechanism and the twisting and take- 56] References Cited up means and holds the two yams separated from each other in such manner that breakage of either or both yarns change UNITED STATES PATENTS the condition of the switch. A switch which is particularly adaptable to this environment is also disclosed. 2,580,387 1/1952 Adams ..57/81 2,353,092 7/1944 Thornton ..57/81 5 Claims, 4 Drawing Figures ama-nmweazv m2 3,672,146

SHEET 2 OF 2 INVENTOR CECIL S. ADAMS a- 1 BY ATTORNEYS YARN BREAK DETECTOR BACKGROUND OF THE INVENTION Stop motion devices which are currently in use on yarn twisting machines have as a principal drawback the placing of excessive tension on each individual strand as it comes from the creel. Many modern yarns are not only delicate in nature but also have special characteristics and this excessive tension on individual yarns is therefore very undesirable since it leads to characteristics in the twisted strand which are very different from those desired. By way of example, if one is attempting to ply a nylon yarn with a dacron yarn, the nylon is the more elastic of the two and will therefore tend to stretch excessively in comparison with the dacron in response to the tension created by the stop motion devices currently in use. The twisted completed yarn therefore, once the tension has been removed, tends to kink and curl in a manner which is very undesirable. The stop motion devices of the prior art which are currently in use with twisting machines are all employed between the creel and the feed means. This requires an additional break detector to be located between the feed rolls and the take-up spindle in order to detect a break of the combined strands or of the traveler.

BRIEF SUMMARY OF THE INVENTION In accordance with the present invention, a novel yarn break detection arrangement is located between the feed means and the twisting and take-up spindle. Whereas the yarns are normally superimposed in their travel from the feed means to the twister and take-up, the present arrangement separates the yarns at this point to sense a break in either or both. i

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagrammatic view showing the essential elements of one section of a twisting machine with the stop motion arrangement of the present invention applied thereto;

FIG. 2 is a perspective view of a yarn break detector switch useful in the practice of the present invention;

FIG. 3 is a perspective view of an alternative form of the switch shown in FIG. 2;- and FIG. 4 is a perspective view of. a still further alternative switch embodiment shown applied to a twister machine of the type having a common or continuous feedroll.

DETAILED DESCRIPTION OF THE DRAWINGS While the following description will be concerned with twisting a'pair of yarns to form a single strand, it will be apparent to those skilled in this art that the invention is applicable to any machine combining an number of strands to form a single strand.-

Referring first to FIG. 1, one section of a twisting machine is somewhat diagrammatically shown. At the'upper portion of the figure are a pair of creel packages and 12, each supplying a yarn 14 and 16, respectively, to a first yarn guide 18. The guide 18 brings the two yarns together and from there they go to a pair of feed rolls 20 and 22. The yarns are wrapped three or four times around the rolls 20 and 22 as a pair and then go upwardly and over a horizontal guide pin 24 following which they proceed in a generally downwardly direction to a further yarn guide 26 and then to the conventional traveler ring 28 and take-up spindle 30.

Positioned between the yarn guide 26 and the horizontal guide 24 is the yarn break detector means of the present invention. In one form of the present invention the detector may include a switch 32 which is conveniently of the type disclosed in the copending application of Adams and Russell Ser. No. 829,87I filed June 3, 1969 now US. Pat. No. 3,555,218. The drop wire 34 connected to the operating shaft of the switch 32 is so arranged at its upper end that it includes a pair of spaced apart yarn guiding means 36 and 38 which are efiective to separate the strands at this point in their travel through the machine.

In the event of breakage of the left hand strand, for example, the slight degree of tension in the right hand strand will then be effective to pivot the drop wire 34 to the left and change the condition of the switch 32. If the right hand strand should break, then the movement of the drop wire is to the right but with the same result, namely, a change in condition of the switch 32. In the event that both strands break, the drop wire 34 will pivot in either a clockwise or counterclockwise direction, it makes no difference which, and again change the electrical condition of the switch 32.

The electrical connections between the machine and the switch 32 are not shown herein because they are not thought to be essential to an understanding of the present invention. Suffice to say, they are conventional and reference may be had, for example, to the aforementioned copending application for a more detailed disclosure.

In lieu of the switch and drop wire as described with reference to FIG. 1, reference may now be had to FIG. 2 for a description of a first alternative embodiment. The operating portions of the switch are shown apart from the electrical connections to the machine for the sake of clarity. A set of stationary contacts 52 are provided in the form of a bifurcated plate member 54 which is rigidly supported on a base portion 56 of the twisting machine and insulated therefrom by a layer of insulation 58. Vertically below the plate 54 there is a shaft or stud member 60 also supported in the base member 56 and on which is joumalled an unbalanced rotary member 62. As shown, the member 62 is eccentrically mounted on the shaft 60 which also serves as the thread guide 24 of FIG. 1. It will be apparent, however, that the same result could be achieved with a concentric mounting but with a rotary weight unbalance by simply adding weight to the member 62 at any desired location. The member 62 carries a movable contact 64 positioned to engage either of the contacts 52, depending upon the direction of rotation of the member 62. A pair of drop wires 66and 68 are also carried by the rotary unbalanced member 62 and the yarns exiting from the feed means of FIG. I are separated and threaded through the drop wires 66 and 68 after which they are reunited and fed to the twisting and take-up means. The slight tension of the yarns is thus employed to hold the member 62 in an unbalanced condition corresponding to a position of the movable contact 64 substantially midway between the stationary contacts 52. In the event of breakage of either or both yarns, it will be apparent that the member 62 will then be free to rotate in either direction to effect engagement of the contact 64 with one of the other of the stationary contacts 52. r

The switch shown in FIG. 3 is similar in many respects to that of FIG. 2. The unbalanced rotary mass 62 of FIG. 2 has simply been divided into two halves 62a and 62b carrying drop wires 66a and 68a and movable contacts 64a and 64b, respectively. The stationary contact member 540 takes the form of a single insulated pin.

As is the case with the previously described embodiments, the yarns leaving the feed roll are again separated and held in a separated condition by the drop wires. To assist in the separation, the embodiment shown in FIG. 3 utilizes a pair of spools 70 and 72 joumaled on a rod 74. As in the previously described embodiments, breakage of either yarn is effective to permit rotation of the corresponding unbalanced rotary member to effect engagement between the movable and fixed contacts.

In FIG. 4 of the attached drawings a switch quite similar in design and function to the one shown in FIG. 2 is disclosed as mounted on a twisting machine of the type which employs a continuous feed roll. The thread guide 60a of this embodiment has been bent as shown in order to accommodate the switch to the position of the common feed roll.

The switches shown in FIGS. 2 to 4, inclusive, are through to have an advantage over the switch of the aforementioned application in the present environment. Due to the rotary unbalanced condition of the operating member, the operation of the switch is more positive particularly in the event both yarn ends break simultaneously. From the foregoing it is believed that those skilled in the art will readily appreciate that there is herein shown and disclosed a novel and useful yarn break detector for controlling a stop motion in a twisting machine and further that useful and novel forms of switches for this application are also disclosed. While preferred embodiments have been herein shown and described, applicant claims the benefit of a full range of equivalents within the scope of the appended claims.

I claim:

1. A yam plying machine including a yarn break detector comprising:

a creel for supplying at least two yarns to be plied, said yarns being spaced from each other;

twisting and take-up means for plying and taking up the plied yarns;

feed means between said creel and said twisting and take-up means, said feed means drawing the spaced yarns from said creel, bringing Such spaced yarns together and supplying them to said twisting and take-up means;

an electrical switch;

drop wire means positioned to separate and maintain said yams spaced-from each other at a point in their travel between said feed means and said twisting and take-up means, said drop wire means being connected to said switch and operative in the event of breakage of one or more of said yarns to change the electrical condition of said switch.

2. A yarn break detector switch for pairs of yarns being plied comprising: 1

a rotationally unbalanced mass mounted for rotation about a substantially horizontal axis;

a pair of contact members rigidly supported adjacent but radially outwardly of said mass and spaced from each other circumferentially of said mass;

a movable contact member carried by and extending from said mass and normally positioned between but spaced from said fixed contact members so as to engage with one or the other upon rotation of said mass in either direction;

circumferentially spaced yarn guide means carried by said mass, said guides when threaded by a pair of spaced yarns under slight tension being effective to hold said mass in an unbalanced condition which corresponds to said movable contact being positioned substantially midway between said fixed contacts;

whereby breakage of either or both yarns permits rotation of said unbalanced mass to effect engagement between said movable contact and one of said fixed contacts.

3. A yarn break detector switch for pairs of yarns being plied comprising:

a pair of rotationally unbalanced masses mounted for rotation about a substantially horizontal axis;

a pair of movable contact members, one carried by each of said masses respectively;

a stationary contact member positioned to be engaged by either of said movable contact members upon rotation of its associated unbalanced mass;

drop wire means carried by said rotary masses and positioned so that when engaged by a pair of running yarns, the masses are held in an unbalanced condition corresponding to a predetermined spacing between said fixed and movable contact members;

whereby breakage of either yarn permits rotation of the respective mass to effect engagement between said fixed creel and said twisting and take-up means and a yarn guide over which the yarns pass between said feed and twisting and take-up means, a yarn break detection arrangement comprismg:

a rotary unbalanced mass mounted for rotation on said thread guide; a pair of fixed contacts; a movable contact member carried by said mass and extending between said fixed contacts; circumferentially spaced drop wire means carried by said mass and so located thereon that when being traversed by the yarns being plied, they are efiective to hold said mass in an unbalanced condition which also corresponds to said movable contact member being spaced substantially midway between said fixed contacts; whereby in the event of breakage of either or both yarns,

said unbalanced mass is released to rotate and effect positive engagement between said movable contact and one or the other of said fixed contacts. 

1. A yarn plying machine including a yarn break detector comprising: a creel for supplying at least two yarns to be plied, said yarns being spaced from each other; twisting and take-up means for plying and taking up the plied yarns; feed means between said creel and said twisting and take-up means, said feed means drawing the spaced yarns from said creel, bringing such spaced yarns together and supplying them to said twisting and take-up means; an electrical switch; drop wire means positioned to separate and maintain said yarns spaced from each other at a point in their travel between said feed means and said twisting and take-up means, said drop wire means being connected to said switch and operative in the event of breakage of one or more of said yarns to change the electrical condition of said switch.
 2. A yarn break detector switch for pairs of yarns being plied comprising: a rotationally unbalanced mass mounted for rotation about a substantially horizontal axis; a pair of contact members rigidly supported adjacent but radially outwardly of said mass and spaced from each other circumferentially of said mass; a movable contact member carried by and extending from said mass and normally positioned between but spaced from said fixed contact members so as to engage with one or the other upon rotation of said mass in either direction; circumferentially spaced yarn guide means carried by said mass, said guides when threaded by a pair of spaced yarns under slight tension being effective to hold said mass in an unbalanced condition which corresponds to said movable contact being positioned substantially midway between said fixed contacts; whereby breakage of either or both yarns permits rotation of said unbalanced mass to effect engagement between said movable contact and one of said fixed contacts.
 3. A yarn break detector switch for pairs of yarns being plied comprising: a pair of rotationally unbalanced masses mounted for rotation about a substantially horizontal axis; a pair of movable contact members, one carried by each of said masses respectively; a stationary contact member positioned to be engaged by either of said movable contact members upon rotation of its associated unbalanced mass; drop wire means carried by said rotary masses and positioned so that when engaged by a pair of running yarns, the masses are held in an unbalanced condition corresponding to a predetermined spacing between said fixed and movable contact members; whereby breakage of either yarn permits rotation of the respective mass to effect engagement between said fixed and movable contact members.
 4. The combination defined by claim 3 including a shaft and a pair of guides mounted for rotation and spaced from each other on said shaft, said guides being substantially aligned with said drop wire means and serving to guide the yarns to said drop wires.
 5. In combination with a yarn twisting machine of the type which includes a creel for supplying at least two yarns to be plied, twisting and take-up means, feed means between said creel and said twisting and take-up means and a yarn guide over which the yarns pass between said feed and twisting and take-up means, a yarn break detection arrangement comprising: a rotary unbalanced mass mounted for rotation on said thread guide; a pair of fixed contacts; a movable contact member carried by said mass and extending between said fixed contacts; circumferentially spaced drop wire means carried by said mass and so located thereon that when being traversed by the yarns being plied, they are effective to hold said mass in an unbalanced condition which also corresponds to said movable contact member being spaced substantially midway between said fixed contacts; whereby in the event of breakage of either or both yarns, said unbalanced mass is released to rotate and effect positive engagement between said movable contact and one or the other of said fixed contacts. 